As a display device including current-driven light-emitting elements, a display device including organic electroluminescent (EL) elements is known. This display device including organic EL elements that emit light does not need backlight necessary in display devices including liquid crystals, and is thus suitable for reducing a thickness of the display device. Furthermore, without restrictions on a viewing angle, the display device including organic EL elements is expected to be used as a next-generation display device. Moreover, regarding organic EL elements, a luminance of each of light-emitting elements is controlled by a value of a current flowing in the light-emitting element. This is different from liquid crystal cells each of which is controlled by an applied voltage.
In the display device including organic EL elements, generally, the organic EL elements each of which is included in a pixel are arranged in a matrix. Switching thin film transistors (TFTs) are provided at cross-points between a plurality of scan lines and a plurality of data lines. Each of the switching TFTs is connected to a gate electrode of a corresponding drive element. By turning on the switching TFT (causing the switching TFT to be an electrically conductive state) via a selected scan line, a data signal voltage is applied to the drive element via a corresponding data line. A device in which organic EL elements are driven by drive elements is called an active matrix organic EL display device.
The active matrix organic EL display device needs to accurately apply data voltages reflecting an image signal to pixel circuits in order to perform highly accurate image displaying. In other words, it is necessary to accurately apply a data voltage between a gate and a source of each drive element, so that the drive element can cause a drive current corresponding to the data voltage to flow in a corresponding light-emitting element to cause the light-emitting element to emit light with a desired luminance.
For example, Patent Literature (PTL) 1 below discloses a method of reducing variations of device properties of a drive element by correcting a shift amount of the drive element.